Sensor device

ABSTRACT

A camera is disclosed which is provided with a sensor device that includes: a substrate having formed thereon which first and second line sensors that are arranged a fixed baseline length apart from each other and a third sensor for receiving light from a field which is arranged on a line in arrangement direction of the first and second line sensors, a first light receiving optical unit for condensing light from the field onto the first line sensor, a second light receiving optical unit for condensing light from the field onto the second line sensor, a third light receiving optical unit for condensing light from the field onto the third sensor, wherein, when focal lengths of the first, second, and third light receiving optical units are assumed to be f 1,  f 2,  and f 3,  respectively, the following condition is satisfied: f 1= f 2≧ f 3.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of application Ser. No. 10/298,736,filed Nov. 18, 2002, now U.S. Pat. No. 6,791,672, the entire disclosureof which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sensor device and an opticalapparatus having the same. In particular, the present invention ispreferable for optical apparatuses such as a digital camera, a videocamera and a film camera that have a range finding sensor for receivinglight from a field to measure a distance to an object existing in thefield and a photometric sensor for receiving light from a field tomeasure luminance of the field and can perform range finding andphotometry with high accuracy.

2. Related Background Art

Up to now, a range finder is well known which measures a distance to asubject in an optical apparatus such as a camera. For example, a rangefinder is well known which, passes light from a subject through twooptical systems arranged at a fixed distance to form a part of subjectimages on separate two line sensors and measures a distance to thesubject by finding a correlation between the two subject images fromoutput signals from the two line sensors.

In addition, a photometer is also well known which measures luminance(brightness) of a subject in an optical apparatus such as a camera. Forexample, the photometer passes light from a field through an opticalsystem to cause an area sensor to receive the light, measures fieldluminance according to an intensity of an output signal of the areasensor, and uses the field luminance for exposure control of the opticalapparatus. Various photometers such as a camera have been proposed whichare devised so as to segment a sensor used in measurement of fieldluminance into a plurality of sensors to detect a difference ofluminance in a main subject to be photographed and its background and,if the difference of luminance is equal to or larger than apredetermined amount, causes a strobe to emit light judging that themain subject is in a back light state, thereby making an exposure stateof the main subject adequate.

Independent separate sensors and optical systems are generally used as aline sensor and an optical system thereof used in the range finder andan area sensor and an optical system thereof used in the photometer.Therefore, if both the range finder and the photometer are mounted on acamera or the like, separate spaces for arranging each of them arerequired, which becomes a restriction on design of the camera or thelike and, at the same time, leads to increase in a size of the camera orthe like. In addition, when an interval between the range finder and thephotometer is large, parallax of a range finding center and aphotometric center occurs. Thus, for example, even if the range findingcenter catches a main subject depending on a distance to a subject, thephotometric center catches the background, which may result in a case inwhich a photographed picture (image) is focused but has inadequateexposure.

In order to solve the above-mentioned problem, it has been proposed tointegrate a range finder and a photometer in U.S. Pat. No. 5,302,997,Japanese Patent Application Laid-Open No. 09-329818 and the like. Inthese proposals, a pair of line sensors for range finding are arranged afixed baseline length apart from each other, and an area sensor forphotometry is arranged in a position between the pair of line sensors.Moreover, both the sensors are formed on one substrate (chip) and, atthe same time, an optical system corresponding to each sensor isprovided.

These proposals have an advantage in that, since it is sufficient toprepare only a space for the above-mentioned integrated device in acamera or the like, restriction on design is eliminated and, at the sametime, since an interval between the range finder and the photometer issignificantly reduced, the problem of parallax of the range findingcenter and the photometric center can be controlled to minimum.

U.S. Pat. No. 5,302,997 and Japanese Patent Application Laid-Open No.09-329818 describe a structure as a sensor to some extent. However,there are no detailed descriptions concerning a structure as a deviceincluding an optical system and a case in which the device isincorporated in an optical apparatus such as a camera. Thus, there arefollowing problems in materializing the inventions as products:

(i) If the range finder and the photometer are separately constituted,the sensors are also separate chips as shown in FIGS. 7A and 7B. A sizeof a chip 301 of range finding sensors 301 a and 301 b generally dependson a size of the range finding sensors. A size of a chip 302 for aphotometric sensor 302 c generally depends on a size of the photometricsensor. Thus, each sensor chip is efficient and is relatively excellentin terms of chip costs.

On the other hand, when the respective sensors are integrated into onechip as shown in FIG. 8, a size of a sensor chip 410 in a verticaldirection in the figure depends on a dimension of a photometric sensor401 c. In addition, a size of the sensor chip 410 in a horizontaldirection in the figure depends on a dimension of range finding sensors401 a and 401 b and a dimension of a photometric sensor 401 c. As isseen from FIG. 8, there are dead spaces above and below the rangefinding sensors 401 a and 401 b. Thus, the sensor chip is less efficientand has extremely high chip costs.

(ii) If the range finder and the photometer are separately constituted,as in a range finder of FIG. 9A and a photometer of FIG. 9B, lightshielding walls 501 to 505 are arranged between optical systems 303 a,303 b and 303 c and sensors 301 a, 301 b and 302 c generally in avertical direction from sensor surfaces such that light other than lightmade incident from the optical systems corresponding to the sensors isnot made incident on the sensors.

When the range finding sensors 301 a and 301 b and the photometricsensor 302 c are integrated into one chip, it is expected that externallight made incident from the photometric lens 303 c is made incident onthe range finding sensor 301 a and 301 b or external light made incidentfrom the range finding lenses 303 a and 303 b is made incident on thephotometric sensor 302 c. In such cases, the incidence of external lightadversely affects range finding accuracy and photometry accuracy,respectively. Thus, U.S. Pat. No. 5,302,997 it is described that it issufficient to provide appropriate preventive walls in order to cope withthis problem. If this is materialized, light shielding walls 601 to 604are constituted in a vertical direction from sensor surfaces 401 a, 401b and 401 c as shown in FIG. 10.

However, the above-mentioned conventional example does not describe asize of each sensor, and sizes of optical systems, a focal length andthe like corresponding to each sensor. When these are taken intoaccount, the light shielding walls cannot be arranged in the verticaldirection with respect to the sensor surfaces.

SUMMARY OF THE INVENTION

The present invention has been devised in view of the above-mentioneddrawbacks and therefore, it is an object of the present invention toprovide a sensor device and an optical apparatus having the same thatare preferable for a digital camera, a video camera, a film camera andthe like, in which a range finding sensor, a photometric sensor and thelike can be easily formed on an identical substrate (chip) whilerealizing miniaturization of the entire apparatus and which can performrange finding and photometry with high accuracy.

A sensor device according to the present invention includes: a substratehaving formed thereon first and second line sensors that are arranged afixed baseline length apart from each other and a third sensor forreceiving light from a field which is arranged on a line in anarrangement direction of the first and second line sensors; a firstlight receiving optical unit for condensing light from the field ontothe first line sensor; a second light receiving optical unit forcondensing light from the field onto the second line sensor; and a thirdlight receiving optical unit for condensing light from the field ontothe third sensor, wherein, when focal lengths of said first, second, andthird light receiving optical units are assumed to be f1, f2, and f3,respectively, the following condition is satisfied: f1=f2≧f3.

Further characteristics of the present invention will be apparent fromaccompanying drawings and descriptions of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B, and 1C are views of photographing screens of a camera forexplaining an embodiment of the present invention;

FIGS. 2A, 2B, and 2C are explanatory views of sensors and a sensordevice for explaining a first embodiment of the present invention;

FIGS. 3A and 3B are explanatory views of the sensors and the sensordevice in the first embodiment of the present invention;

FIGS. 4A and 4B are explanatory views of sensors and a sensor device ina modification of the first embodiment of the present invention;

FIGS. 5A and 5B are explanatory views of sensors and a sensor device ina second embodiment of the present invention;

FIGS. 6A and 6B are explanatory views of sensors and a sensor device ina modification of the second embodiment of the present invention;

FIGS. 7A and 7B are explanatory views of a range finding sensor and aphotometric sensor in a conventional example;

FIG. 8 is an explanatory view of a range finding and photometricintegral sensor in the conventional example;

FIGS. 9A and 9B are explanatory views of structures of a range finderand a photometer in the conventional example;

FIG. 10 is an explanatory view of a range finding and photometricintegral sensor in the conventional example; and

FIG. 11 is a schematic view of an optical apparatus of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

First Embodiment

FIGS. 1A, 1B, and 1C to FIGS. 4A and 4B are views for explaining a firstembodiment of the present invention.

Note that it is assumed that, as a range finding method in thisembodiment, a so-called image deviation system is used which finds arelative positional relationship between two object images based onobject images on a predetermined surface photographed by an object lensto perform focus detection.

In an optical apparatus such as a camera, the optical apparatus cansatisfy its function if a field of view to be subjected to range findingin a photographing screen (range finding field of view) is generallyoblong with respect to the photographing screen. However, the field ofview to be subjected to photometry (photometry field of view) isgenerally required to be a wide area including a central part of aphotographing screen. This will be described with reference to FIGS. 1A,1B, and 1C. These figures show an example of photographing in aphotographing screen 1 by a camera. A main subject 2 who is in black ina bright background is photographed in a so-called back light state.

In FIG. 1A, reference numeral 11 denotes an area corresponding to arange finding line sensor (sensor) on the photographing screen 1. Thearea is in a shape covering an area in which a distance to a person whois the main subject 2 can be measured.

In addition, in FIG. 1B, reference numeral 12 denotes an areacorresponding to a photometric area sensor (sensor) on the photographingscreen. The area is in a shape covering an area larger than the areacovered by the range finding line sensor 11, that is, an area includingthe person who is the main subject 2 as well as mountains in thebackground. Therefore, an output from the photometric area sensor 12becomes an average output of luminance of the entire photographingscreen 1. If exposure control of the camera is performed based oninformation of the average output, a photograph in an adequate exposurestate over the entire screen can be photographed even in a back lightscene as in FIG. 1B.

On the other hand, if an area of a photometric area sensor 13 is smallwith respect to the photographing screen 1 as shown in FIG. 1C and is ina shape covering only an area of a person 2, although adequate exposurecan be obtained for the person 2, it is imagined that an exposure stateof the background is not,adequate (in the example of FIGS. 1A to 1C, anexposure state of the person in the back light state who is the mainsubject 1 is assumed to be adequate, and the background is not taken atall, a so-called white void phenomenon). Thus, on the photographingscreen 1, a range of the photometric area sensor 13 is desirably in arange equal to or larger than the range finding line sensor 11.

Here, a device realizing the above-mentioned contents is as describedbelow.

FIG. 2A is a view of a sensor chip 20 including a range finding sensorand a photometric sensor and a corresponding optical system 202 viewedfrom a direction perpendicular to an optical axis direction. FIG. 2B isa view of the sensor (sensor chip) 20 of FIG. 2A viewed from the opticalsystem 202.

In FIGS. 2A and 2B, reference numeral 202 denotes a light receivingoptical system for condensing light from a field, which has lightreceiving lenses for range finding (first and second light receivingoptical systems) 202 a and 202 b and a light receiving lens forphotometry (third light receiving optical system) 202 c. Referencenumeral 201 denotes a sensor, in which a pair of range finding linesensors (first and second line sensors) 201 a and 201 b and aphotometric area sensor (third sensor) 201 c and a circuit (not shown)for processing outputs from these sensors are integrated into one chip,and sizes of the chip are h in a vertical direction and w in ahorizontal direction in FIG. 2B.

Further, focal lengths f1, f2, and f3 of the three light receivinglenses 202 a, 202 b, and 202 c are the same, respectively. The rangefinding sensors 201 a and 201 b have sizes h1 and h2 in the verticaldirection and sizes w1 and w2 in the horizontal direction in FIG. 2B,respectively, such that a sensor area as shown in FIGS. 1A and 1 b isobtained on the photographing screen 1. In addition, the photometricsensor 201 c has a size h3 in the vertical direction and a size w3 inthe horizontal direction.

In this embodiment, for simplification of explanation, the followingdescription is made assuming that w1 is equal to w2 and h1 is equal toh2.

In addition, an optical axis 202 a 1 of the light receiving lens forrange finding 202 a and an optical axis 202 b 1 of the light receivinglens 202 b are arranged a baseline length B1 apart from each other.Similarly, a center of a size in horizontal direction of the rangefinding sensor 201 a and a center of a size in horizontal direction ofthe range finding sensor 201 b are arranged the same distance as thebaseline length B1 apart from each other. The baseline length B1 dependson required measurement accuracy. In general, measurement accuracy isbetter when a focal length between a baseline length and a lightreceiving lens for range finding is longer.

Here, since the focal length f1, f2, and f3 of the three light receivinglens 202 a, 202 b, and 202 c are equal, in order to make a photometricarea larger than a range finding area on the photographing screen 1, arelationship among the sizes of the three light receiving sensors 201 a,201 b, and 201 c are set as follows:h1<h3w1<w3,provided, however, since the photometric sensor 201 c is arrangedbetween the pair of range finding sensors 201 a and 201 b,w 3<(B 1−w 1).

In this embodiment, since the third sensor is arranged between the firstand second line sensors as a structure of the sensor device, aninfluence of parallax is eliminated when the first to third sensorsreceive light from a field.

In addition, since sensors for measuring a distance to an objectexisting in a field are the first and second line sensors as a structureof the sensor device, it becomes possible to use the sensor device as arange finder. At the same time, the sensor device is allowed to measurea distance of an appropriate area of the field.

Further, since the third sensor is a sensor for measuring luminance of afield, it becomes possible to use the sensor device as a photometer. Atthe same time, the sensor device is allowed to measure light in anappropriate area in the field.

As is seen from the above description, the size in vertical direction hof the sensor constituted by the one chip 20 is substantially dominatedby the size in vertical direction h3 of the photometric sensor 201 c.Similarly, the size in horizontal direction w is substantially dominatedby the baseline length B1 and the sizes in horizontal (baseline length)direction w1 and w2 of the range finding sensors 201 a and 201 b.

In short, since factors for dominating a chip size reside in the sensorsof two types, the range finding sensors 201 a and 201 b and thephotometric sensor 201 c, the entire chip size can be reduced byapproximating a size of the sensor of one type to a size of the sensorof the other type.

FIG. 2C shows a sensor chip. 10 with a reduced size compared with thatin FIG. 2B. In FIG. 2C, a size in vertical direction of the photometricsensor 103 c is set to be h3 a (h3 a<h3), and the size in verticaldirection of the photometric sensor 103 c is approximated to that of therange finding sensors 103 a and 103 b, whereby the size in verticaldirection of the sensor chip 10 is set to h1 (h1<h). In this case, asize in horizontal direction w3 a (w3 a<w3) of the photometric sensor103 c is reduced with the same ratio as in reducing the size in verticaldirection. When focal lengths of light receiving lenses corresponding tothe sensors of the range finding sensors 103 a and 103 b and thephotometric sensor 103 c are equal, since the areas of the range findingsensors 103 a and 103 b on the photographing screen 1 are as shown inFIG. 1A, there is no specific problem. However, the area of thephotometric sensor 103 c on the photographing screen 1 may be reduced asshown in FIG. 1C.

Thus, in this embodiment, the focal length f3 of the light receivinglens for photometry 104 c is set as follows as shown in FIG. 3A to solvethe above-mentioned problem:f3≦f1  (1),provided, however,f1=f2  (2).

That is, in this embodiment, the focal lengths f1, f2, and f3 are set asfollows:f1=f2≧f3,whereby a size of a sensor chip can be reduced remarkably. Thus, aninexpensive sensor device is made. To explain this more in detail, thefocal length f3 of the light receiving lens for photometry 104 c isreduced at the same ratio as in reducing the size of the photometricsensor 103 c. That is, the focal length f3 is set so as to satisfy thefollowing condition:(wa 3/w 3)=(f 3/f 1),whereby an area of a photometric sensor on a photographing screenequivalent to that in FIG. 1B is secured.

FIG. 3B shows the same view as FIG. 2C. As is seen from the sensor chip10 in the figure, the dead spaces above and blow the range findingsensors 103 c and 103 b are extremely reduced, thereby realizing aneffective sensor arrangement.

In other words, when it is assumed that a dimension in verticaldirection of the range finding sensors 103 a and 103 b is h1, adimension in horizontal direction of the range finding sensors 103 a and103 b is w1, a dimension in vertical direction of the photometric sensor103 c is h3 and a dimension in horizontal direction of the photometricsensor 103 c is w3, and a focal length of the light receiving lens forrange finding 104 a is f1 and a focal length of the light receiving lensfor photometry is f3, in order to set an area of the photometric sensor103 c larger than or equal to an area of the range finding sensors 103 aand 103 b on the photographing screen 1, a condition is as follows inthe vertical direction of the photographing screen 1:(f 3/f 1)≦(h 3/h 1)  (4),provided, however, f1=f2.

Since the area of the photometric sensor 103 c can be set equal to orlarger than the area of the range finding sensors 103 a and 103 b on thephotographing screen 1 by satisfying Expression (4) when the device ismounted on a camera or the like, it becomes possible to control thecamera or the like such that a high quality image that is in focus withadequate exposure can be obtained.

In the horizontal direction of the photographing screen 1, it issufficient that the following condition is satisfied:(f 3/f 1)≦(w 3/w 1)  (3),provided, however, f1=f2.

Since the area of the photometric sensor 103 c can be set equal to orlarger than the area of the range finding sensors 103 a and 103 b on thephotographing screen 1 by satisfying Expression (3) when the device ismounted on a camera or the like, it becomes possible to control thecamera or the like such that a high quality image that is in focus withadequate exposure can be obtained.

To explain Expressions (3) and (4) more in detail, when it is assumedthat a size of each sensor is equal as follows:h1=h3  (5)w1=w3  (6),in order to set the area of the photometric sensor 103 c equal to orlarger than the area of the range finding sensors 103 a and 103 b on thephotographing screen 1, it is sufficient to set the focal lengths f1 andf3 as follows:f3≦f1  (7).It is seen that satisfying, in particular, Expression (7) among theabove-mentioned Expressions (3) to (7) contributes significantly toreducing a size of a sensor chip.

In addition, in this embodiment, a relationship among theabove-mentioned Expressions (3) to (7) can be applied not only to astructure in which the photometric sensor 103 c is arranged between thepair of range finding sensors 103 a and 103 b but also to a case inwhich the photometric sensor 103 c is arranged on the outside of thepair of range finding sensors 103 a and 103 b as shown in FIGS. 4A and4B.

Moreover, the contrivance in the case in which the range finding sensorsand the photometric sensor are integrated is described in theabove-mentioned example. However, for example, even if it is consideredto replace the photometric sensor in the above-mentioned example with asensor for remote control reception and integrate the range findingsensors with the sensor for remote control reception, it is expectedthat the same problem will occur because the sensor for remote controlreception is required to receive signal light from a wider field of viewcompared with the range finding sensor.

Thus, in this embodiment, the third sensor is changed to a sensor forreceiving a remote control signal from the outside as a structure of thesensor device, whereby it becomes possible to use the sensor device as aremote controlled light receiving device. At the same time, the sensordevice is allowed to receive a remote control signal from an appropriatearea of a field.

That is, in the case in which the same problem is expected, it isdesirable to apply the relationship of the above-mentioned Expressions(3) to (7).

In addition, the optical system 202 constituted by the light receivinglenses 202 a, 202 b, and 202 c shown in FIG. 2A, the optical system 104constituted by the light receiving lenses 104 a, 104 b, and 104 c shownin FIG. 3A, and the optical system 104 constituted by three lightreceiving lenses shown in FIG. 4A may be constituted as an integrallymolded three-eye lens, respectively.

Further, although one area sensor is assumed as the above-mentionedphotometric sensor, a multi-segmented sensor as disclosed in U.S. Pat.No. 5,302,997 may be used as the photometric sensor.

Second Embodiment

Next, a second embodiment of the present invention will be described.

In FIGS. 3A and 3B, the range finder and photometer is illustrated inwhich the size of the photometric sensor 103 c is reduced and the focallength f3 of the light receiving lens for photometry 104 c is madeshorter than the focal length f1 of the light receiving lenses for rangefinding 104 a and 104 b, whereby the chip size of the sensor is reduced.

Here, when a focal length is reduced while keeping an opening area of alight receiving lens constant, an F number (focal length of alens/diameter of a lens opening) indicating brightness of a lensdecreases. However, it is generally difficult to manufacture a lens withan F number of 1 or less. Therefore, if a focal length of a lens isreduced significantly, a diameter of a lens opening is required to bereduced such that the F number becomes larger than one.

On the other hand, the smaller an F number of a light receiving lens(the brighter a lens), with a better S/N ratio a range finder and aphotometer can be provided. Thus, a space created by reducing the focallength f3 and the opening diameter of the light receiving lens forphotometry can be utilized to increase the opening diameter of the lightreceiving lens for photometry within a range in which the F number islarger than one.

FIGS. 5A and 5B are explanatory views illustrating the abovedescription.

A structure of the sensor chip 10 in FIGS. 5A and 5B is identical withthat described in FIGS. 3A and 3B. In FIG. 5A, reference numeral 105denotes a light receiving optical system for condensing light from afield, which has light receiving lenses for range finding 105 a and 105b and a light receiving lens for photometry 105 c.

Focal lengths f1 and f2 of the light receiving lenses for range finding105 a and 105 b are set to the same focal length f1 with which the lightreceiving sensors for range finding 103 a and 103 b in FIG. 5B have thesensor area as shown in FIG. 1A on the photographing screen. Inaddition, a focal length of the light receiving lens for photometry 105c is set to a focal length f3 with which the light receiving sensor forphotometry 103 c in FIG. 5B has the sensor area as shown in FIG. 1B onthe photographing screen. At the same time, an opening diameter of thelight receiving sensor for photometry 103 c is reduced such that an Fnumber becomes larger than one.

On the other hand, in the light receiving lenses for range finding 105 aand 105 b, in order to increase an S/N ratio of a range finding signal,an opening diameter is increased within a range in which an F numberdoes not become equal to or smaller than one and to a degree in whichthe light receiving lenses for range finding 105 a and 105 b do notoverlap the light receiving lens for photometry 105 c.

Moreover, FIG. 5A shows light shielding walls that are required when thesensors and the lenses are incorporated in a device. Reference numerals61 to 64 shown by broken lines show the case in which the lightshielding walls are constituted in a vertical direction from a sensorsurface just like the light shielding walls 601 to 604 shown in FIG. 10.

In FIG. 5A, the light shielding wall 61 extends vertically toward thelight receiving lens for range finding 105 a from a left outer sideviewed from an object side of the range finding sensor 103 a (this isthe same in the following description). The light shielding wall 62extends vertically toward the light receiving lens for range finding 105a in a manner to avoid the light receiving lens for photometry 105 cfrom a part between the range finding sensor 103 a and the photometricsensor 103 c. The light shielding wall 63 extends vertically toward thelight receiving lens for range finding 105 b in a manner to avoid thelight receiving lens for photometry 105 c from a part between the rangefinding sensor 103 b and the photometric sensor 103 c. The lightshielding wall 64 extends vertically toward the light receiving lens forrange finding 105 b from a right outer side of the range finding sensor103 b.

As is seen from FIG. 5A, the light shielding walls 61 to 64 do notbecome obstacles for light made incident from the light receiving lensfor photometry 105 c but become obstacles for light made incident fromthe light receiving lenses for range finding 105 a and 105 b. That is,although the opening diameter of the light receiving lenses for rangefinding 105 a and 105 b are increased in order to obtain a high S/Nratio of a range finding signal, the increase in the opening diameterdoes not lead to an increase in the S/N ratio because incident light isshielded by the light shielding walls 61 to 64.

In FIG. 5A, reference numerals 51 to 54 denote light shielding walls inthis embodiment.

In FIG. 5A, the light shielding wall 51 extends obliquely toward a leftouter side of the light receiving lens for range finding 105 a from aleft outer side of the range finding sensor 103 a. The light shieldingwall 52 extends in a manner to avoid the light receiving lens forphotometry 105 c and obliquely toward a right outer side of the lightreceiving lens for range finding 105 a from a part between the rangefinding sensor 103 a and the photometric sensor 103 c. The lightshielding wall 53 extends in a manner to avoid the light receiving lensfor photometry 105 c and obliquely toward a left outer side of the lightreceiving lens for range finding 105 b from a part between the rangefinding sensor 103 b and the photometric sensor 103 c. The lightshielding wall 54 extends obliquely toward a right outer side of thelight receiving lens for range finding 105 b from a right outer side ofthe range finding sensor 103 b.

In this way, the light shielding walls 51 to 54 do not become obstaclesfor light made incident from the light receiving lens for photometry 105c as a matter of course and then, the light shielding walls 51 to 54 canbe constituted such that it is less likely for the light shielding walls51 to 54 to become obstacles for light made incident from the lightreceiving lenses for range finding 105 a and 105 b. Thus, it is possibleto secure an S/N ratio of a range finding signal sufficiently.

Here, the light shielding wall 51 may be extended in a verticaldirection with respect to the sensor surface from the left outer side ofthe light receiving lens for range finding 105 a and the light shieldingwall 54 may be extended in a vertical direction with respect to thesensor surface from the right outer side of the light receiving lens forrange finding 105 b only from the viewpoint of the S/N ratio of a rangefinding signal. However, a structure from the range finding sensor 103 ato the light receiving lens 105 a is required to be symmetrical withrespect to a line from the center of the range finding sensor 103 a tothe center of the light receiving lens 105 a. If the structure from therange finding sensor 103 a to the light receiving lens 105 a should beasymmetrical, assuming that external light other than light from anobject of measurement is reflected on the light shielding walls, aninfluence of the reflection is not equal in the right and left parts onthe sensor. This results in a range finding error. Therefore, thestructure from the range finding sensor 103 a to the light receivinglens 105 a is required to be symmetrical.

That is, in a structure of a range finder and photometer having theoptical system as shown in FIGS. 5A and 5B, light shielding walls forshielding an optical path for range finding from other optical paths areformed so as to be extended in a direction in which a distance betweenthe light shielding walls widens toward the range finding lenses 105 aand 105 b from the range finding sensors 103 a and 103 b, whereby thestructure of the light shielding walls 51 to 54 can be made symmetrical,and it becomes possible to secure a sufficient S/N and alleviate ameasurement error (wrong range finding).

In addition, it is desirable to apply the structure of the lightshielding walls 51 to 54 not only to the structure in which thephotometric sensor 103 c is arranged between the pair of range findingsensors 103 a and 103 b but also to a case in which a sensor chip 111 isused on which the photometric sensor 103 c is arranged on the outside ofthe pair of range finding sensors 103 a and 103 b as shown in FIGS. 6Aand 6B.

In FIG. 6A, reference numerals 71 to 75 denote light shielding walls.

In addition, as long as the above-mentioned structure of the opticalsystem is adopted, it is desirable to apply the above-mentionedstructure of the light shielding walls even if other sensors are used asthe photometric sensor 103 c and the range finding sensors 103 a and 103b.

In addition, the optical system 105 constituted by the light receivinglenses 105 a, 105 b, and 105 c shown in FIG. 5A and an optical system105 constituted by three light receiving lenses 105 a, 105 b and 105 cshown in FIG. 6A may be constituted as an integrally molded three-eyelens, respectively.

Note that, although sensor chips 103, 110, 111, 201, 301, 302, and 401are generally arranged in a predetermined package such that the sensorchips are easily incorporated in a device, illustration of the packageis omitted in each embodiment for simplification of descriptions.

In addition, although one area sensor is assumed as the above-mentionedphotometric sensor, a multi-segmented sensor as disclosed in U.S. Pat.No. 5,302,997 may be used as the photometric sensor.

Next, an embodiment of a single-lens reflex camera (optical apparatus)having the sensor device of the present invention will be described withreference to FIG. 11.

In FIG. 11, reference numeral 40 denotes a camera main body; 41, aphotographing lens; and 42, photographing means, which consists of afilm, a CCD or the like. Reference numeral 43 denotes a finder system,which has a focusing glass 45 on which a subject image is formed, apentagonal prism 46 as image reversing means, and an ocular lens 47 forobserving a subject image on the focusing glass 45. Reference numeral 44denotes a quick return mirror. Reference numeral 48 denotes a sub-mirrorand 49 denotes a sensor device in accordance with the present invention.

Light from a subject passes through the photographing lens 41. Then, thelight passes through a light transmitting portion (half mirror surface)of the quick return mirror 44 and is reflected on the sub-mirror 48 tobe made incident on the sensor device 49. Range finding and photometryare performed by the sensor device 49.

As described above, the sensor device of the present invention isapplied to electronic cameras such as a video camera and a digital stillcamera and a film camera, whereby an optical apparatus having highoptical performance is realized.

According to the present invention, a sensor device preferable for adigital camera, a video camera, a film camera and the like and anoptical apparatus having the same can be realized, in which a rangefinding sensor, a photometric sensor and the like can be easily formedon an identical substrate (chip) while realizing miniaturization of theentire apparatus and which can perform range finding and photometry withhigh accuracy.

According to the present invention, a range finding sensor, aphotometric sensor and the like are appropriately formed on an identicalsubstrate (chip) and, moreover, an optical system for guiding light tothe sensors is appropriately set, whereby a high accurate sensor deviceand an optical apparatus having the same can be realized.

1. A sensor device comprising: a first and a second sensors arranged atan interval of predetermined baseline length so as to take a correlationbetween output signals therefrom; a third sensor for receiving lightfrom a field, wherein the third sensor is arranged on a surface on whichthe first and the second sensors are arranged; a first optical unit forrelating light from a field to the first sensor; a second optical unitfor relating light from a field to the second sensor; and a thirdoptical unit for relating light from a field to the third sensor;wherein focal lengths of the first and the second optical units aredifferent from that of the third optical unit; and wherein the thirdsensor is a sensor measuring a brightness in order to control exposure.2. A sensor device according to claim 1, wherein the third sensor isdisposed between the first sensor and the second sensor.
 3. A sensordevice according to claim 1, wherein the first and the second sensorsare line sensors.
 4. A sensor device according to claim 1, wherein thefirst and the second sensors are sensors for measuring a distance to asubject.